Enhancement of CO2 adsorption and separation in basic ionic liquid/ZIF-8 with core–shell structure

Abstract

A novel strategy was proposed to improve the performance of gas separation in nano-materials, by fabricating a core–shell structure out of the basic ionic liquid ([Emim]₂[IDA]) and zeolitic imidazolate framework (ZIF-8). The [Emim]₂[IDA]/ZIF-8 exhibits a remarkable CO₂ adsorption capacity of 14 cm³ g⁻¹ at 298 K and 20 kPa, the ideal selectivity of CO₂/N₂ is as high as 10⁴ and CO₂/CH₄ is 348 at 298 K and 100 kPa, which are much higher than the CO₂ adsorption capacity (4.3 cm³ g⁻¹) and the selectivity (S_CO2/N2 = 7.4, S_CO2/CH4 = 2.7) of ZIF-8. This work could pave the way for designing advanced nanostructures tailored for gas separation.